Glossary term
DMARC / DKIM / SPF
Also: Email authentication, Email spoofing protection
Three standards that together authenticate email senders and impede spoofing. SPF authenticates the sending IP, DKIM signs the content, DMARC links both via the From header and defines the policy.
SPF: TXT record in DNS listing permitted sending IPs. Limitation: breaks on forwarding.
DKIM: cryptographic signature of email header and/or body, verifiable via DNS public key. Works even across forwarding.
In practice
DMARC: policy layer (none/quarantine/reject), reporting (aggregate + forensic) and alignment between From header and SPF/DKIM. Roadmap: monitoring 4-8 weeks, then quarantine, then reject. 2024-2026: Yahoo, Google and Microsoft enforce DMARC for bulk senders.
Related terms
Supply Chain Risk
Risks from the software and hardware supply chain: compromised open-source packages, build-pipeline attacks, updates with backdoors, sub-suppliers without audit trail. Mandatory under NIS2 Art. 21 (d) and DORA Art. 28 (sub-outsourcing).
Dealbreaker
A hard requirement that immediately disqualifies an option if not met, independent of weighted scoring. Dealbreakers enforce non-negotiable constraints (EU hosting, specific certifications, data residency) and prevent weak options from winning on aggregate scores.
Decision memo
A short structured document that captures why a decision was made, the options considered, the criteria and trade-offs, the stakeholders involved and the accepted risks. A good decision memo is auditable months later.
Defensible record
A single versioned artefact that captures a decision in enough structure, with enough evidence and stakeholder context, that it can be defended under audit, in a board review, or 12 months later when the original team is no longer in place.
DLP
Software category for detecting and preventing unauthorised data outflow. Operates on endpoints, network and cloud. Classifies content (regex, fingerprinting, ML) and enforces policies.
DORA
EU regulation on digital operational resilience in the financial sector. Directly applicable since 17 January 2025. Five pillars: ICT risk management, incident management, resilience testing including TLPT, third-party governance, information sharing.
DORA ICT risk management
The EU Digital Operational Resilience Act regulates the operational resilience of financial entities against ICT risks, with particularly prescriptive expectations around ICT third-party risk management (Art. 28) and contractual arrangements (Art. 30).
DPIA
Mandatory assessment under GDPR Art. 35 where processing is likely to result in high risk to the rights and freedoms of natural persons. Required e.g. for systematic evaluation, large-scale processing of special categories and systematic monitoring of public areas.